Self-activating endoluminal device

ABSTRACT

An improved endoluminal device. The device includes at least a control element (such as a guide wire) connected to a surrounding sheath and an elastic bias section to control changes to a bias force formed between the control element and the sheath. By applying an external force at a proximal end of the device, the shape can change between varying degrees of deformed shapes and an undeformed shape. In this way, both ease of insertion into the body lumen and anchoring to the lumen is promoted. A distal end of the assembly can be made to change shape for improved steerability, anchoring or both. In a particular form, the anchoring section can work as a floating parachute-like device to pull the assembly by means of the flow in the body lumen, while in a more particular form, the floating parachute-like device may be modified to act as a filter for trapping emboli.

This application claims the benefit of U.S. Provisional Application Ser.No. 60/514,806, filed Oct. 27, 2003.

BACKGROUND OF THE INVENTION

When a guide wire assembly is placed into a vascular, biliary, orurogenital lumen, the operator has to maintain it in place by holdingthe proximal end still. When a catheter or related endoluminal device isbrought over the assembly, the assembly's distal end may start moving,because the relatively rigid catheter influences the geometry of thefloppy guide wire, especially in tortuous arteries. The catheter willtend to straighten the guide wire assembly, thus creating a pull forceon the guide wire tip, which causes an undesired movement. When thedistal end of the assembly moves back in a proximal direction, it mayslip out of the target artery, and if this happens, it will be necessaryto pull the devices back to repeat the procedure. This is often the caseif the guide wire makes a bend before the most flexible tip enters thetarget artery.

Previous attempts at developing a medical line anchoring system includeusing a simply-structured device that permits a portion of a cathetertube or similar medical article to be easily anchored to a patient,desirably without the use of tape, needles or suturing. In one exemplarydevice, shown and described in U.S. Pat. No. 6,447,485 to Bierman, aunitary retainer desirably includes a base connected to a cover by wayof a flexible hinge. The retainer is attached to a flexible anchor padincluding an adhesive bottom surface, which can be attached to thepatient's skin. Such is an example of anchoring outside the body. Inother approaches, elongated members that can lock themselves in place ina body site can be used. For example, in U.S. Pat. No. 6,544,262 toFleischman discloses electrodes with an expandable tip that anchors theelectrode to a body lumen or related tissue. In another method, the wireis held in place is by means of an inflatable balloon near the distalend, as shown in for example U.S. Pat. No. 6,595,989 to Schaer.Likewise, in U.S. Pat. No. 6,254,550 to McNamara et al, a preformed wireguide is shown, which can anchor itself in a side artery (for example arenal artery), because the wire has been treated to obtain a strong bendat the entrance of the side artery. At the site of this bend the wirecan anchor itself, because at the given location the target artery makesa strong angle with the main access artery (aorta). Therefore the wirewill hang with its bent section on the entrance of the side artery. InU.S. Pat. No. 4,884,579 to Engelson, anchoring is achieved by giving thedistal section of the guide wire a less slippery surface. While such anapproach increases the grip, care must be exercised during insertionwhen minimal friction is required, as too strong of a grip mayadditionally damage the vessel wall.

Guide wire assemblies with a steerable tip are well-known in the art.Some types have a shapeable tip that can be bent to a desired anglebefore insertion. While the angle enables the operator to find a wayinto side arteries, its relatively fixed nature means that once in thebody, the angle can not be changed. Therefore it is better to have aremote control, where the curvature of the tip is steered by proximalactuation. In one example, hollow guide wires include a floppy tip,where a pre-bent wire can be advanced into the floppy region to changethe curvature. For example, in U.S. Pat. No. 6,599,254 to Winters, ahollow guide wire with a tension wire attached to the floppy tip at aneccentric place is disclosed. If the operator pulls the tension wirerelative to the guide wire, the tip will bend. The curvature can beadjusted, dependent on the pull force. In another example, U.S. Pat. No.5,741,429 to Donadio III et al gives a hollow guide wire with a seriesof slots made in the tube wall at the place where more flexibility isdesired. Manufacturing processes for the apparatus, including slottedhypotube, for use as a catheter, a guide wire, a catheter sheath for usewith catheter introducers or a drug infusion catheter or guide wire aredisclosed. The manufacturing process includes creating a pattern ofslots or apertures in a flexible metallic tubular member, by processesincluding but not limited to, electrostatic discharge machining (EDM),chemical milling, ablation and laser cutting. These slots or aperturesmay be cut completely or partially through the wall of the flexiblemetallic tubular member. Other slotted configurations are also possible.For example, in U.S. Patent Application Publication 20030069522, aslotted medical device is described, with a plurality of pairs of slotscut into the body to make it more flexible in bending while maintainingadequate torsional stiffness.

In all cases, the actuation is controlled from the proximal end. This isdone with some additional tool or actuation means, which will in generalhave a different geometry and typically a larger diameter than the guidewire assembly itself. Such an actuation means attached to the proximalend section makes it impossible to slide the catheter over this proximalend. Therefore, the actuation means has to be uncoupled to bring thecatheter over this proximal end. This is the case for over the wirecatheters as well as for rapid exchange catheters. This isdisadvantageous, because in placing the catheter over the guide wire,the operator can not hold the distal section of the guide wire assemblyin a fixed, anchored position.

Accordingly, there exists a need for an endoluminal device that iscapable of being manipulated at a proximal end while having its distalend situated in, steered through and anchorable in a body lumen.Further, there exists a need for an endoluminal device that is in areadily-activated state to facilitate shape changes capable of producingenhanced levels of steerability and anchorability.

SUMMARY OF THE INVENTION

This need is met by the present invention, where the placement of aguide wire assembly or related medical device in a body lumen issimplified by reconfigurable features, including self-anchoring andsteerable attributes. Possible embodiments include, but are not limitedto, a hypotube, a catheter, steerable tip, an electrode, an angioplastyballoon, a drain, a dilator, a distal protection filter, a filter, abasket, an anchor, a floating anchor, an occlusion device, a lead, adrain, a guide wire, a catheter sheath for use with catheter introducersor a drug infusion catheter or guide wire and stylets.

The self-anchoring feature enables the assembly to have an anchorsituated at an axially distal location on the assembly, while leavingradial dimensions of the assembly proximal to the anchor such thatendoluminal and related treatment devices (for example, catheters) maybe slid over the proximal end. By being reconfigurable, theself-anchoring and steerable features can be kept in either a deformedor undeformed shape, thereby improving maneuvering the assembly into abody lumen and proper placement in the desired location. Thisreconfigurable feature is achieved by varying a built-in axial forcebetween a wire or related control element and a tubular sheath thatsubstantially encases the control element. Connectivity between thecontrol element and sheath, coupled with forced longitudinal movement ofthe control element inside the sheath, causes changes to the shape ofthe anchoring section and steerable section. The inherent bias resultingfrom the connectivity between assembly's the control element and sheathmeans the assembly is in its deformed state when left alone. In order tobring the device into its insertion state by changing the geometry ofone or both of the steerable and anchoring sections, simple actuation atthe assembly's proximal end is all that is required.

According to an aspect of the invention, a medical device for use in abody lumen is disclosed. The device includes a tubular sheath and anelongate control element. Both the sheath and the control elementinclude proximal and distal ends. The sheath further includes at leastone reconfigurable section disposed between its proximal and distalends, and an elastic bias section. The control element (which in oneparticular embodiment is a wire) is sized to allow longitudinalplacement thereof within the sheath, the sheath and control elementfixedly attached to one another such that a tensile force is imposed bythe sheath on the control element. The tensile force is sufficient tobias the medical device in a deformed first shape that can be changed byvariation of the tensile force. In changing the tensile force, themedical device assumes a second shape different from the deformed firstshape. In the present context, a device is considered to exist in adeformed shape when the inherent bias force causes the device to assumea shape different than the device would exhibit in a state of rest if nosuch force were imposed. For example, with a tension force existingbetween the control element and the sheath, a bend in one or both endsof the device produced by this tension would cause a (preferablyelastic) deviation from a normally straight shape. In such case, thebent shape is considered deformed. Similarly, radial or related outwardexpansion of the sheath caused by an axial compression of the portionintermediate the connected ends would amount to a deformed shape.Contrarily, a device is considered to exist in an undeformed shape whenany inherent bias forces have been overcome such that the device assumesa shape commensurate with no net forces acting upon it.

The elastic bias section is disposed proximal relative to thereconfigurable section, and is configured to vary the axial length ofthe sheath's reconfigurable section, thereby producing the variation ofthe tensile force between the sheath and the wire. The elastic biassection assists in compensating the relative movement between thecontrol element and the sheath in the reconfigurable section by allowingrelative movement of the sheath and the control element in the vicinityof the proximal end of the device. To achieve this, the elastic bassection acts as a bias spring to create an axial force necessary to keepthe reconfigurable section in its deformed state. Actuation (such as bya user or operator) of the bias spring will cause a release of the axialforce on the control element and so allow the spontaneous return of oneor both of the anchoring and steerable sections (both discussed below)from a deformed shape to an undeformed or lesser deformed shape.

Optionally, the variation of the tensile force used to overcome the biasforce may be a reduction in the tensile force. In another option, thedistal end of the wire is fixedly attached to the corresponding distalend of the sheath, and the proximal end of the wire is fixedly attachedto the corresponding proximal end of the sheath while the elastic biassection is in an axially compressed state. This forms a tensile force onthe wire such that when left in an undisturbed state, the device has abias tension. An additional option includes coupling a tool to at leastone of the wire or the sheath to help regulate relative axial positionsbetween the wire and the sheath. This allows changes to the built-inbias to effect transition between the first substantially deformed shapeand the undeformed or lesser deformed second shape. The tool may furtherinclude markings, displays or related indicia to apprise a user of anamount of bias remaining in the elastic bias section. Similarly, thetool comprises indicia configured to apprise a user of an amount ofdeformation associated with the second shape. The tool comprises aconnector to facilitate its removable attachment to the wire, sheath orboth. In one form, the connector is a lock. In a more specific form, thelock comprises a threaded connection between the tool and the sheath.

The reconfigurable section of the sheath may be made up of numerouscomponents. For example, it may include the aforementioned steerablesection disposed adjacent the respective distal ends of the controlelement and the sheath. The steerable section may be configured to allowbending along at least a portion of its length. This bend defines onepossible form of the deformed second shape mentioned above. These bendsmay be facilitated by forming at least one slot in the sheath. This slotor slots may be oriented in various directions, including axially,tangentially, circumferentially or in any angle between 0 and 90 degreesrelative to the longitudinal axis of the device. In another form, thesteerable section may be made up of numerous steerable regions, therebyallowing for additional insertion capability in tortuous lumens. In thiscase, the bends formed in each of the plurality of steerable regions canbe biased (through, for example, the aforementioned slots or relatedplaces of weakening formed in the sheath) in directions independent ofthe remainder of the plurality of steerable regions. Another form ofpreferential bending can be achieved by including a coil spring in thesheath. To provide additional bias capability, a rigidity element may beplaced asymmetrically in the coil spring. A similar approach can beincorporated by placing a longitudinal reinforcement along the outersurface of the sheath such that it produces an axially asymmetricrigidity.

In place of (or in addition to) the steerable section discussed above,the reconfigurable section of the sheath may include an anchoringsection. This section's contribution to the device's deformed firstshape corresponds to an expanded state. Contrarily, when the anchoringsection is in an unexpanded state, it contributes to the device'sundeformed or lesser deformed second shape. In one form, the expandedstate comprises a substantially radially expanded state. In anotherform, the expanded state comprises a substantially helical shape. Theanchoring section may include a plurality of struts with slots definedtherebetween, giving the anchoring section a basket-like configuration.These struts can be oriented along a substantially axial dimension ofthe sheath, or can be placed in an off-axis direction. In one particularexample, the anchoring section is a simple Nitinol basket, cut by meansof a laser and then heat treated in its stretched, cylindrical state.When the distal and proximal ends of such a basket are pulled closer toeach other by means of the internal control element under tension, thestruts will bend outward, resulting in an increased basket diameter. Byattaching the control element to the distal end of the basket andsubsequently releasing the pulling force (such as by axially pushing onthe elastic bias section at the proximal end of the device), the strutswill return to their straight state, causing the basket to collapse. Inanother embodiment, the anchoring section may be made up of a mesh layerconfigured as a collapsible basket. In this way, both anchoring andfiltering (discussed below) functions can be achieved by a singleexpandable/collapsible device disposed in the sheath. In a particularform, the wire mesh basket may be made of a self-collapsing material,such as Nitinol or related shape-memory materials.

In addition, the reconfigurable section of the sheath can be made up ofboth a steerable section and an anchoring section, where preferably thesteerable section is disposed downstream of the anchoring section. Atleast one of the steerable and anchoring sections may be madeelastically deformable in response to the variation of the inherent biasforce.

Regardless of whether the anchoring section is provided with thesteerable section or alone, it may additionally include a flexiblepolymer layer disposed over the struts. The polymer layer may beconfigured as a filter, bag or related device. For example, to be afilter, apertures or related perforations may be formed through thelayer surface. Configured as a bag, the flexible polymer layer has anopen proximal entrance mouth and a closed distal end. The proximalentrance mouth of the bag can be coupled to the struts at a distallocation relative to a largest diameter defined by the struts in theanchoring section's expanded state. When configured as a bag, thehydraulic pressure difference inherent in a flowing bodily fluid (suchas blood) can be exploited to push the device with a partially-deployedfloating anchor deeper into the body lumen. For example, by having thebag be either partially or fully expanded, the pressure differencebetween the proximal and distal sides of the bag provides a drivingforce that propels the device downstream. When the bag has no apertures,the application of the fully expanded bag in the body lumen may causethe lumen to become fully occluded, which may be useful in specificapplications. If a pattern of apertures is made into the layer, thefloating anchor does not occlude the lumen, allowing it to be used as afilter for embolic protection. In another embodiment, the filter may bemade of a wire mesh instead of a perforated polymer layer. Such a wiremesh filter may be attached directly to the anchoring section struts ina manner similar to the polymer layer. The wire mesh filter may beintegrated with the anchoring section, wherein the wire mesh structurebecomes expandable by the same relative axial displacement between thecontrol element and the surrounding sheath.

The device may further include one or more endoluminal devices that canslidably fit over the sheath, at least when the sheath is in thesubstantially undeformed second shape. The endoluminal device can be atleast any of a catheter, steerable tip, stent, filter, angioplastyballoon, drain, dilator, filter, basket, anchor, floating anchor,occlusion device, guide wire, stylet, electrode, lead, drain, cathetersheath for use with catheter introducers or a drug infusion catheter, aswell as combinations of the above. Similarly, the device itself may be acatheter, steerable tip, stent, filter, angioplasty balloon, drain,dilator, filter, basket, anchor, floating anchor, occlusion device,guide wire, stylet, electrode, lead, drain, catheter sheath for use withcatheter introducers or a drug infusion catheter, or combination of theabove. Furthermore, materials making up the control element and sheathcan be made from polymers, metals or similar structural constituents, orcombinations thereof. In a particular form, the metal can be ashape-memory metal. These materials are especially valuable forapplications requiring reconfigurable, bistable or related components.

According to another aspect of the invention, a guide wire assembly foruse in a body lumen is disclosed. The assembly includes a tubularsheath, wire and elastic bias section to control the variation in theforce between the sheath and the wire. The sheath defines a proximalend, a distal end and at least one reconfigurable section disposedintermediate the proximal and distal ends. The wire defines a proximalend and a distal end that are placed substantially adjacent to andsubstantially aligned with the respective ends of the sheath tofacilitate a fixed attachment. As with the previous aspect, a forceimposed by the sheath on the wire sufficient to bias the assembly in asubstantially deformed first shape can be overcome by a variation in theforce such that upon application of the variation in force, the assemblyassumes a less deformed second shape different from the deformed firstshape. The elastic bias section can be disposed in or otherwise formedin the sheath to effect this variation in force. In one particular form,the sheath itself can form the necessary elastic bias section, where apolymer sheath has enough longitudinal elasticity to act as acompression spring. Such a configuration simplifies the overallconstruction. Slots or related cut-outs could be included to facilitatean enhanced longitudinal elastic response.

Optionally, the assembly includes a tool coupled to the elastic biassection, thereby facilitating control of the variation in force betweenthe sheath and wire. In another option, the reconfigurable section orsections comprise a steerable section disposed adjacent the distal endof the control element and the sheath. As previously described, thesteerable section is bendably responsive to the variation in the force.Also as previously described, the assembly may include an anchoringsection (either with or without the steerable section) expandablyresponsive to the variation in the force. The anchoring section mayassume a substantially expanded state when the assembly is in the firstshape, and an unexpanded state when the assembly is in the undeformedsecond shape.

According to still another aspect of the invention, a medical devicewith a transformable distal shape for use in a body lumen is disclosed.The device includes a hollow elongate member and an elongate controlelement sized to freely move longitudinally in the hollow elongatemember. The hollow elongate member and the elongate control element arefixedly attached to each other at their respective proximal and distalends. If the elongate member and control element were to be disassembledand separately measured in an undeformed state, the length of theelongate control element would be shorter than the hollow elongatemember. Thus, when assembled and connected at their respective ends, theelongate member and the control element impose a bias force on eachother.

Optionally, the hollow elongate member is provided with at least twosections that can be elastically deformed in a longitudinal direction.These sections include an elastic bias section located adjacent theproximal end of the elongate member, and a reconfigurable sectionlocated intermediate the proximal and distal ends of the elongatemember. The reconfigurable section is cooperative with the elastic biassection such that relative movements between the elongate controlelement and the elongate member produce a change in shape of thereconfigurable section. As previously discussed, a biasing force iscaused by stored energy in the elastic bias section. This force issufficient to bring the reconfigurable section into a deformed shape. Aremovable tool can be used for length control and consequent change inshape of the reconfigurable section, where the change in shape of thereconfigurable section includes shape changes suitable for insertinginto a body lumen. To allow for various shapes between a fully deformedshape and an undeformed shape, the tool cooperates with the elastic biassection to produce intermediate positions for the reconfigurablesection.

As previously discussed in conjunction with other aspects of theinvention, the reconfigurable section may include a plurality ofsteerable sections, and an expandable anchoring section responsive tochanges in force between the elongate member and the control element.Each of the plurality of steerable sections may be configured to beresponsive to different levels in force between the elongate member andthe control element. Furthermore, they may preferentially deform intosimilar shapes and directions, or do so independently of one another. Atleast one of the plurality of steerable sections may define a pattern ofslots formed in a wall of the elongate member. In addition, at least oneof the plurality of steerable sections comprises an additionalasymmetric reinforcing element, where the asymmetric reinforcing elementcan be disposed on the outer surface of the elongate member.

The anchoring section may also form a basket as previously described.The basket is made up of a plurality of struts configured to facilitatechanges of shape between a first deformed shape and a second shape. Aflexible polymer layer may additionally be disposed over at least aportion of the basket. This layer may be configured as a bag such thatthe layer defines an open proximal entrance mouth. This mouth may belocated distal of the radially widest portion of the basket. The polymerbag may be used to form a pressure difference between proximal anddistal sides of the bag. In one form, the bag can be used to at leastpartly occlude a body lumen. In another form, the polymer layer includesapertures formed in its surface. In this configuration, the bag isadapted for use as a filter for catching debris that pass through thebody lumen.

The tool can be made removable from the device. This allows thereconfigurable section to remain in the body lumen even after removal ofthe tool. The device may further include one or more treatment devicesconfigured to be deployed inside the body lumen over the proximal end ofthe elongate member. Treatment devices may include guide wires,catheters, steerable tips, stents, filters, angioplasty balloons, drain,dilators, filters, baskets, anchors, floating anchors, occlusiondevices, guide wires, stylets, electrodes, leads, drains, cathetersheaths for use with catheter introducers or a drug infusion catheter,or combinations of the above. The tool is applied to control thegeometry of the reconfigurable section while either or both of thedevice and the treatment device are moved through or positioned in thebody lumen. The tool may also include a display or related indiciaconfigured to inform an operator about an operational status of thereconfigurable section. Materials making up the elongate member mayinclude polymers (including high-strength polymers), metal and metalwith enhanced radio-opacity (including magnetic resonance imaging)features. It will be appreciated by those skilled in the art that thecontrol element may be made from a different material than the elongatemember. The length difference of the elongate member and the controlelement can be adjusted at or near a proximal fixation end of the deviceby a releasable locking means. This locking means may form part of thetool described above, or be a separate member.

According to yet another aspect of the invention, a method of insertinga medical device into a body lumen is disclosed. The device includes atubular sheath and an elongate control element, each defining proximaland distal ends that can be coupled together. In addition, the sheathincludes one or more reconfigurable sections disposed intermediate itsproximal and distal ends, as well as on the elastic bias section. Theelastic bias section, sheath and control element are attached to oneanother such that a bias force is imposed by the sheath on the controlelement through the elastic bias section. This bias force is sufficientto keep the device in a deformed first shape. The method includesintroducing the device into the lumen and imposing a force on the deviceto overcome the bias force, thereby causing the medical device to assumea less deformed (or undeformed) second shape different from the deformedfirst shape.

In one optional form, imposing a force on the device comprises imposinga force on a proximal end of the device. As with previous aspects, atool can be coupled to the device such that the force being imposed onthe device is transmitted through the tool. One way to impose a force onthe device is to remove a tensile force on the control element. In oneparticular option, the reconfigurable section in the sheath comprises asteerable section. This steerable section can (as previously discussed)define numerous steerable regions. One or more of these steerableregions can be made to deform in a substantially similar direction uponthe imposing a force on the device to overcome the bias force. Inanother configuration, the steerable regions can be made to deform in asubstantially different direction from the other regions. As previouslydiscussed, the deformed first shape can comprise a bend in the one ormore steerable regions of the steerable section. Moreover, at least oneplace of weakness can be formed in the steerable section to establish atleast one preferential direction for promoting the deformed first shape.By way of example, the place of weakness can be one or more slotsdefined in the sheath. As previously discussed, the steerable sectionmay comprise a coil spring placed along the sheath. This coil spring canhave the same outer diameter as the sheath. In a preferred embodiment,the coil spring replaces a section of the sheath material. A rigidityelement may also be employed asymmetrically in the coil spring, as in amanner similar to that previously discussed. The steerable section mayalso include a longitudinal reinforcement disposed asymmetrically alongthe outer surface of the sheath. The transitioning from a first deformedshape to a second shape may also be achieved through an anchoringsection similar to that previously described. In one particular way, theamount of expansion in the anchoring section can be controlled to allowit to come in significant contact with the inner wall of the body lumen,or to a radial dimension less than that sufficient to contact aninterior wall of the lumen but more than the second shape.

As before, the method may include coupling a mesh or a polymer layer tothe anchoring section. This layer can form a bag, filter or relateddevice, all as discussed above. In these forms, the layer can be used tofilter a fluid through the bag, or (in the case of a partially-expandedbag) to take advantage of flowing fluid through or into the bag tofacilitate downstream movement of the device. In an alternateembodiment, rather than having a wire mesh be placed over a series ofexpandable and collapsible struts, the anchoring section may be formedby a wire mesh configured as a basket, thereby reducing the amount ofredundant structure. As with the wire mesh coupled to the struts, thiswire mesh basket can be made to expand or collapse, depending on theamount of force imposed on the device. Also as before, a tool can becoupled to the proximal end of the device to effect transition betweenthe first deformed shape and the second undeformed or lesser deformedshape of the steerable section, anchoring section or both. In additionto the basket-like shape of the anchoring section that can be formedwhen alternating struts and slots are used, the anchoring section may beconfigured as a helical shape upon the imposing of the bias force. Inaddition, the steerable section can be made to cooperate with theanchoring section such that both assume a helical shape upon theimposing of the bias force. The amount of change in the bias force canbe made proportional to the amount of force needed to change betweenfirst and second shapes for the anchoring and steerable sections,thereby allowing them to deform or undeform in a particular order. Forexample, while a three Newton tensile force may be sufficient to keepthe steerable section deformed, a larger force (such as a five Newtontensile force) may be required to keep the anchoring section deformed.Moreover, varying the tensile force between upper and lower limits mayallow varying degrees of lesser deformation, such as a partiallyexpanded anchoring section or a lesser amount of bend in the steerablesection.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of the preferred embodiments of thepresent invention can be best understood when read in conjunction withthe following drawings, where like structure is indicated with likereference numerals and in which:

FIG. 1 shows portions of an endoluminal device in an undeformedinsertion state according to an embodiment of the invention;

FIG. 2 shows a detail of a steering section of the device of FIG. 1,where a part of the steering section is deformed;

FIG. 3 shows a detail of the device of FIG. 1 with a pattern of slotsdisposed in its sheath;

FIG. 4 gives an alternative detail of the device of FIG. 3, showing aseparate flexible part;

FIG. 5 shows a detail of the steering section of the device of FIG. 1,where a larger part of the steering section is deformed than in FIG. 2;

FIG. 6 shows a detail of the steering section of the device of FIG. 1,where an even larger part of the steering section is deformed than inFIG. 5;

FIG. 7 shows an embodiment of the device of FIG. 1, including a helicalanchoring section in a deformed state, and steerable section in adeformed state;

FIG. 8 shows an alternate embodiment of the anchoring section in adeformed state;

FIG. 9 shows an embodiment of an elastic bias section of the device ofFIG. 1 near the device's proximal end;

FIG. 9 a shows the proximal section of FIG. 9 and the distal section ofFIG. 8 assembled together;

FIG. 9 b shows the outer element of the assembly of FIG. 9 a with thewire removed;

FIG. 9 c shows the wire of the assembly of FIG. 9 a with the outerelement removed;

FIG. 10 shows a tool used to maneuver the wire and attached adjacent theproximal end of the guide wire assembly of FIG. 9;

FIG. 10A shows an alternate embodiment for a releasable connection ofseveral parts at the proximal end of the guide wire assembly;

FIG. 10B shows yet another embodiment for a releasable connection ofseveral parts at the proximal end of the guide wire assembly;

FIG. 11 gives another embodiment of the invention, with a floatinganchor;

FIG. 12 gives still another embodiment of the invention in which theanchor section works as a filter;

FIG. 13 a shows a first state of a device with a combination of theanchoring section of FIG. 8 and the steerable section of FIGS. 1 and 2,where the elastic bias section is compressed into a preloaded state;

FIG. 13 b shows a second state where the elastic bias section isslightly compressed relative to the bias section of FIG. 13 a;

FIG. 13 c shows a third state where the elastic bias section is slightlycompressed relative to the bias section of FIG. 13 b;

FIG. 13 d shows a fourth state where the elastic bias section isslightly compressed relative to the bias section of FIG. 13 c; and

FIG. 13 e shows a fifth state where the elastic bias section is slightlycompressed relative to the bias section of FIG. 13 d.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring first to FIG. 1, a tubular-shaped guide wire assembly 10 isshown. While the present disclosure emphasizes a device for guide wireapplications, it will be appreciated by those skilled in the art thatbut the same principle can be used for a range of different endoluminalapplications, including catheters, steerable tips, stents, filters,angioplasty balloons, drains, dilators, filters, baskets, anchors,floating anchors, occlusion devices, guide wires, stylets, electrodes,leads, drains, catheter sheaths for use with catheter introducers or adrug infusion catheter, or related medical devices. At one end, theassembly 10 includes a proximal end 11 configured to be gripped by anoperator or connected to a handle, tool or related device. The opposingdistal end 12, configured to be inserted into a body lumen (not shown),terminates in a tip. Guide wire assembly 10 includes a sheath 13 thatcan encase wire 14 that acts as a control element for steering andanchoring purposes.

In general, it is advantageous if the distal end 12 of the guide wireassembly 10 is relatively compliant or floppy, while the majority of thelength should be kink resistant, pushable, bendable and able to transmittorsional forces from the proximal to distal ends 11, 12 in order tomaneuver the assembly 10 accurately. The sheath 13 can be chosen fromany wire or hypotube material suitable for guide wire or catheterapplications. One specifically suitable material is superelasticNitinol, a nickel-titanium alloy with shape-memory properties that iswell-known for its flexibility, pushability, biocompatibility and kinkresistance. In one configuration, the majority of the length of the tubemay made of metal while an anchoring section (discussed in more detailbelow) may be made from a relatively soft and flexible material thateasily deforms when the wire 14 being moved causes an axial compressionin the sheath 13. The wire 14 can be made of a high strength yetflexible polymer. If improved visibility for MRI or relatedradio-opacity is needed, additional markers of materials like gold,platinum, silver, tungsten, iridium or the like may be used at specificlocations on either the wire 14 or sheath 13. Other material choicesinclude metals and related materials for improved strength, stiffness orvisibility for MRI or radio-opacity.

Sheath 13 is made up of numerous distinct sections, including elasticbias section 15, located near the proximal end 11, long intermediatesection 10 a, anchoring section 16 and steerable section 17. Whileintermediate section 10 a does not possess significant longitudinalelasticity, elastic bias section 15 and anchoring and steerable sections16, 17 are made in such a way that they respond with a considerableshape change to the forces that are generated between sheath 13 andcontrol wire 14. Steerable section 17 includes a floppy tip 17 a andconnector 17 b, the latter used to attach a distal end of the wire 14 tothe wall of sheath 13. Floppy tip 17 a may be relatively short, and mayeven be integrated with steerable section 17, in which case connector 17b is placed at the most distal end 12. An important attribute associatedwith the anchoring section 16 and steerable section 17 is that therelative movement between the wire 14 and the sheath 13 produce a shapechange that is sufficient to change the size, shape or both of theassembly 10, depending on the insertion and anchoring needs. Such shapechanges are especially valuable if the surrounding tissue has acylindrical shape, as non-axisymmetric or varying-diameter lumens tendto form their own anchoring points. In addition, the difficulty oftraversing sharply-bent lumens is reduced if the distal end 12 can bemade to approximate the lumen's change in shape. Accordingly, thesteerable section 17 can form one or more curves. Both the steerablesection 17 and the anchoring section 16 can be activated by axiallymoving wire 14 relative to sheath 13. This can be effected by anattachable tool (discussed later), placed at or near the proximal end 11of guide wire assembly 10 to interface with both ends of biasing section15. Once the biasing tension force has been applied between wire 14 andsheath 13, the proximal ends of wire 14 and sheath 13 can be connectedpermanently (as shown later in FIG. 9) or in a releasable way (as shownlater in FIGS. 10A and 10B).

Steerable Features

Referring next to FIGS. 2, 5 and 6, embodiments depicting a guide wireassembly 10 with relative movement of wire 14 inside sheath 13 to effectvariations in the steerable section 17 are shown. In one form, there canbe a pull force applied to the proximal end 18 of wire 14. This pullforce will cause a change of shape of steerable section 17, where floppytip 17 a extends to the distal end 12 of guide wire assembly 10. Thisshape change can be made to depend on the amount of force applied. Inthis way, a gradient in shape change is achieved in order to combinesteerability upon insertion with anchoring after insertion.

FIG. 2 shows a detail of steerable section 17 of guide wire assembly 10adjacent its distal end 12 in bent form, with regions X, Y and Zdefining distinct steerable portions of section 17 which have been mademore flexible than the relatively rigid intermediate section 10A. Assuch, the steerable section 17 can be tailored such that distal end 12flexes in a controlled way in a preferred direction. For example, slots(described below in conjunction with FIG. 3), cut-outs and relatedplaces of weakness may be formed in region X to facilitate preferentialbending. The slots can be made in such a way that region X flexes at thelowest force, region Y at a higher force and region Z at a still higherforce. It will be apparent to those skilled in the art that the relativeposition of regions X, Y and Z can be chosen arbitrarily, and that thenumber of such regions is dependent on the type of use. Accordingly,such regions may be overlapping or blended in a different way.Similarly, the functions of floppiness, steerability and anchoring maybe mixed within such regions. In the present figure, only region X isdeformed, because only a small proximal pull force is applied to wire14; with increasingly larger pull forces, regions Y and Z would alsobecome deformed, such as described next.

Referring with particularity to FIG. 5, when the pull force is increasedrelative to that of FIG. 2, the flexure caused in region X is followedby an additional flexure of region Y. Depending on how the slots orrelated deformation-enhancing elements are formed, the curvature ofregion Y can be in the same direction as for region X, or in theopposite direction (as shown), or in a different plane (not shown).Referring with particularity to FIG. 6, the pulling force is furtherincreased, causing region Z to change shape as well. As with region Xdiscussed above, regions Y and Z may include slots or similar places ofweakness built into sheath 13. This gradual change of the guide wireassembly 10 geometry at regions X, Y and Z enables more precise controlof the distal section 12. A display (not shown) may be used to provideindicia of the force applied or the relative movement between sheath 13and the wire 14. In one form, the display may be an electronic device,while in another, it may be made up of graduated markings disposedbetween the sheath 13 and wire 14. This enables the operator to keep theguide wire assembly 10 straight upon insertion, steer the distal end 12to maneuver it into side lumens and then finally anchor it in thedesired lumen location in order to proceed with using a catheter orrelated device.

Referring next to FIGS. 3 and 4, features promoting the curvature ofsteerable section 17 shown in FIGS. 2, 5 and 6 are shown. Referring withparticularity to FIG. 3, examples of an asymmetric pattern of deep slots19 and shallow slots 20 formed in sheath 13 promotes the preferentialdeformation of the guide wire assembly 10 previously discussed andshown. The slot patterns 19, 20 in the distal end 12 of guide wireassembly 10 not only enable steerability, but also makes that portion ofthe sheath 13 more flexible. This promotes insertability of the assembly10 into a desired location within the body lumen by elasticallydeforming a section of the wall of sheath 13. For example, deep slots 19are located such that upon pulling wire 14, the shortening of region Xwill be larger at the concave side (where deep slots 19 are located)than at the convex side, where shorter slots 20 may be located. Aspreviously mentioned, similar slots are also made in region Y and Z,although the slot pattern may be different than in region X, as theseregions need more force to bend.

Referring with particularity to FIG. 4, while the choice of making slots19, 20 in the sheath 13 is one way to promote the axial deformation ofregions X, Y and Z to achieve the shape change shown in FIGS. 2, 5 and 6upon pulling on wire 14, it will be appreciated by those skilled in theart that other ways may also be employed. For example, flexible coilspring 21 with an asymmetric rigidity disposed between adjacent coilsmay be formed in sheath 13 to effect similar bending. For example, a gapbetween adjacent coils 22 is left open on one side; this gap is variableupon spring compression. Opposite the gaps, rigidity element 23 isplaced between successive coils. In one form, rigidity element 23 is apolymer, glue or related material that resists change of lengths betweenadjacent coils. Other materials may be used to create a flexible sectionsimilar to coil spring 21 to effect guide wire assembly 10 bending if apull force is applied to wire 14. This includes the use of polymertubing where, for example, an eccentric lumen holds the wire 14. Anotherpossibility is the use of an eccentric reinforcement (not shown), actingas a spine, which is embedded in the wall of the polymer tubing. In suchcase, both ends of the flexible section are connected to the remainderof the sheath 13. This connection between this flexible section and thesheath 13 may be achieved by any known technique, including the use ofwelding, crimping, brazing, gluing or embedding in a surrounding covermaterial.

Anchoring Features

Operation of the anchoring section 16 causes changes in guide wireassembly 10 diameter by means of local radially outward expansion inanchoring section 16. As with the aforementioned steerable section 17,discussed in conjunction with FIGS. 2, 5 and 6 above, a pulling biasforce is applied between wire 14 and sheath 13. By varying this force(such as through an operator pushing on wire 14) to cause a relativemovement between wire 14 and sheath 13, a corresponding change of shapeof anchoring section 16 can be effected. As with shape changes insteerable section 17 made possible with pulling on wire 14, changes inshape of anchoring section 16 can be made to depend on the amount offorce applied. In this way, a gradient in shape change is achieved inorder to combine steerability upon insertion with anchoring afterinsertion. The anchoring features of the anchoring section 16 can beaugmented by inherent anchoring features produced in steerable section17. For example, steerable segments X, Y and Z of section 17 can, whenthey are in their bent state, increase the friction with the lumen wall,thereby producing an additional anchoring function.

Referring next to FIG. 8 in conjunction with FIG. 1, the anchoringsection 16 is shown in the shape of an expandable basket 80, made byforming longitudinal slots 81 in the wall of sheath 13 to define struts82 therebetween. Connector 32 is used in a manner similar to that of theconnection point 17 b depicted in FIG. 1, where the distal end of thewire 14 is connected to a crimped end 33 or related attachment means. Asbefore, distal end 12 may be tapered and similarly attached. Therigidity of the struts 82 is such that they will have the tendency tostraighten out along the axial dimension of guide wire assembly 10 if aforce sufficient to overcome the bias force is imposed on wire 14. Thisis made possible by the larger exertion of the sheath 13 relative towire 14 to define a first, retracted radial dimension that coincideswith an insertion state of the guide wire assembly 10, such as shown inFIG. 1. In operation, the pulling on wire 14 inherent in the bias forcebrings the distal end 12 toward proximal end 11, and because of theattachment of wire 14 to sheath 13, basket 80 shortens as the struts 82gradually bend outward, causing sheath 13 to assume an expanded radialdimension shown in FIG. 8. Preferably, the expanded radial dimensioncorresponds to the inner dimension of the lumen wall so that basket 80tightly anchors the sheath 13 to this lumen. Although the struts 82 andslots 81 are shown arranged in a generally longitudinal (i.e., axial)pattern, it will be appreciated by those skilled in the art that theyneed not be so oriented, but may be made in different angles andpatterns to tailor the behavior of the anchoring section 16 to aparticular lumen need.

While the anchoring section 16 may be formed in the wall of sheath 13 asshown in order to keep the design simple and monolithic, it can inanother form be made from a different component and built in the guidewire assembly, thereby allowing the use of potentially differentmaterials. One example of a non-monolithic embodiment would be the useof a separate wire mesh basket (not shown) for anchoring section 16,attached to a sheath 13 formed from a more conventional steel tube. Inthis way, the wire mesh basket could be incorporated that performs thesame duties as the struts 82. An additional benefit (as described laterin conjunction with FIG. 12) is that the wire mesh basket, by having thesame collapsible and expandable features of the strut version ofanchoring section 16 is that it can also perform filtering functionswithout the need for a separate layer attached to struts. In one form,such a basket could be made from Nitinol or related shape-memorymaterials.

One way of producing such a device would be the use of a steel tube withfor example an outer diameter of 0.35 mm, which is glued inside the tubeof which the Nitinol basket is made. The inside diameter of the baskettube could be 0.40 mm and the outside diameter 0.45 to 0.50 mm. As such,the wire 14 slides without friction through the steel tube. Furthermore,the anchoring section 16 may have different geometries than those shownin FIG. 8. For example, the struts 82 could be longer and placed partlyparallel to the longitudinal axis, or the struts 82 could be placed in azigzag pattern (not shown) to improve the radial strength or wallapposition of the basket. Such additional struts may also be used toconnect extra devices to the surface of the basket. Besides theanchoring function (which increases longitudinal friction), the radialforce of the basket may also be used for different applications. Forexample, it can work as a dilator, for example for applying a force to alesion or to post-dilate a region in the lumen that has been stented.

Operation of the Guide Wire Assembly

FIG. 9 highlights the portion of guide wire assembly 10 between proximalend 11 and elastic bias section 15, the latter including unobtrusiveflexibility features useful in enabling the assembly's steering andanchoring functions. Length L in elastic bias section 15 represents theunloaded length of the elastic bias section 15. The variable lengthfeatures are made possible by either connecting a separate tubularspring with length L in elastic bias section 15 to the sheath 13, orproviding sheath 13 over a length L with a pattern of slots (not shown,but similar to slots 19, 20 of FIG. 3) that create the same effect. Ineither approach, the small radial dimensions ensure that the flexible,elastic features fit within the footprint of the sheath 13. In thelatter approach, sheath 13 is still of unitary (i.e., one-piece)construction, thereby preserving its inherent torque and bucklingresistance while providing an increase in axial elasticity. Instead ofmaking slots in elastic bias section 15, the use of a sheath 13 with apolymer section, which has enough longitudinal elasticity, can alsoenable a compression spring-like bias.

As previously mentioned, guide wire assembly 10 is pre-loaded to keepthe wire 14 in a state of tension. To achieve this, the proximal end 18of wire 14 is attached to the corresponding end of sheath 13 whileelastic bias section 15 of sheath 13 is compressed to length L1.Attachment is effected by permanently crimping a separate attachmentelement 92 onto the proximal end 18 of wire 14, or by crimping togetherthe respective ends of sheath 13 and wire 14. Alternative attachmentschemes are also available, including gluing, welding or relatedbonding. After attachment, elastic bias section (presently shown in theform of a compressed spring) 15 attempts to return to length L. In sodoing, the bias force created by the compressed spring 15 produces atension load in wire 14 that exceeds the force needed to collapse theanchoring section 16 relative to the shape shown in FIG. 8. Thus, thefixed relationship between the wire 14 and sheath 13 at distal end 12 ofguide wire assembly 10, in conjunction with the fixed relationshipbetween the wire 14 and sheath 13 by attachment element 92 at proximalend 18 of guide wire assembly 10 and the bias force caused by thecompressed spring 15 described above, keeps the wire 14 under constanttension as long as the guide wire assembly 10 is not manipulated byexternal forces. As a consequence, the guide wire assembly 10 remains inits expanded radial dimension of FIG. 8 during this period of noexternal forces. Moreover, both the steerable section 17 and theanchoring section 16 are active, meaning that without application of anexternal force, such as from an operator, they are in their respectivebent and expanded states. Upon application of an external compressionforce (such as by an operator) to spring 15, the steerable and theanchoring sections 17, 16 can assume their straight and non-expandedform shown in FIG. 1. In addition, the operator can slide a catheter orother endoluminal prosthetic devices as previously discussed over atleast portions of the guide wire assembly 10 while the assembly is inits expanded radial dimension, knowing that it has reached the desiredlocation in the body and that it holds its achieved position there.

In operation, if the elastic bias section 15 is further compressed untilit reaches length L2, the tension force in wire 14 will drop to zero andthe distal sections 16 and 17 will return to their unbiased state suchthat the guide wire assembly 10 has a relatively straight, unexpandedand smooth shape, as shown in FIG. 1. Gradual control of the distalstate of guide wire assembly 10 takes place in control range ΔL that isequal to the difference between the lengths L1 and L2.

Referring next to FIG. 10, tool 100 can be used to improve thefunctionality of the guide wire assembly 10. With tool 100, it will beeasier to activate the steering and anchoring functions in gradualsteps, thereby providing enhanced control of the geometry of the guidewire assembly 10, including intermediate positions between the fullyunactivated (retracted) state and the fully activated (expanded) state.In addition to preventing the buckling of elastic bias section 15 or theinadvertent deployment of the anchoring or steerable sections 16, 17,tool 100 can be used to provide smooth length control and an accurateposition read-out. This read-out, which may be in the form of a displayas previously discussed, can give information about the status of thereconfigurable section, which is especially beneficial when the operatorwants to know about intermediate states of deployment or actuation ofthe anchoring or steerable sections 16, 17. In one form, the tool 100resembles a tubular member that may be mounted over the entire proximalend of sheath 13. As shown in the figure, tool 100 is made from twoseparate pieces that can be made to vary along their axial dimensionrelative to one another over length ΔL. Proximal part 101 is connectedto and holds the proximal end 11 of sheath 13, while distal part 102 oftool 100 is clamped on the surface of sheath 13 distally of elastic biassection 15 with a screw lock 103 made from a thread or snap connection.Proximal part 101 further includes an elongate cylindrical section 104onto which distal part 102 may telescopically fit. The distal end ofcylindrical section 104 forms a flange 105 to allow a snap-fitengagement with distal part 102. Flange 105 can move freely through anenlarged diameter chamber 108 that is formed in distal part 102. In sucha construction, parts 101 and 102 can be slid over the proximal end 11of guide wire assembly 10 until the operator feels that the end of theinternal cavity formed in proximal part 101 touches the proximal end 11of the guide wire assembly 10 as shown. The operator then tightens lock103 (such as by screwing) to distal part 102. This ensures the operatorthat length ΔL is available for controlling the shape of the remotesteerable and anchoring sections 17, 16 respectively. One way this canbe achieved is by visually checking a gap formed between complementarysurfaces 106 and 107 of respective proximal and distal parts 101 and102. The operator may further adjust this gap to a smaller length tomake the guide wire assembly 10 coincide with a slightly bent orexpanded shape when it is desired to have the steering section 17 beangled for better maneuverability or the anchoring section 16 to be inan intermediate state of deployment. This is achieved as follows: theoperator can control a part of ΔL by first pushing surfaces 106 and 107closer to each other before tightening lock 103. Upon tightening by lock103, the steerable and anchoring sections 17, 16 will not returncompletely to their straight unbiased state when the operator pushessurfaces 106 and 107 to each other. For example, the anchoring section16 may collapse while the steerable section 17 is still in its bentstate, commensurate with the amount of force placed on wire 14. Byunlocking lock 103, the operator can simply remove tool 100 to enablesubsequent placement of the catheter or related device over the proximalend 11 of the guide wire assembly 10.

By having the wire 14 be pre-loaded in a manner similar to thatpreviously discussed in conjunction with FIG. 9, the guide wire assembly10 can be kept in an activated state even though an operator is notmanipulating the wire 14 relative to the sheath 13. When the operatorpushes on proximal part 101, the guide wire assembly 10 becomesdeactivated. Tool 100 may be provided with thread, allowing preciseaxial distance control by relative rotation between the proximal anddistal parts 101, 102. Proximal locking made possible with lock 103allows the operator to maintain the shape of one or both of thesteerable and anchoring sections 17, 16 when the guide wire assembly 10is left alone. The operator may permit some free axial play between theproximal end 11 of guide wire assembly 10 and proximal part 101. In analternate form, proximal part 101 and cylindrical section 104 are notone single part, but separated, so that the length of cylindricalsection 104 can be adjusted by means of a threaded connection (notshown) between cylindrical section 104 and the internal cavity ofproximal part 101.

A well known alternative for tool 100, which may be used for theadjustment of ΔL, is the mechanism commonly found in ball point pens,where a simple axial movement of part 101 automatically causes a lockingof the displacement ΔL, thus bringing the device into an undeformedstate. By pressing another time on part 101, it will unlock again andthe device returns immediately to its deformed state. Such ball pointpen actuators are also made in different embodiments, for example withaxial translation caused by rotating the proximal knob. Such devices canvery well be used to move part 101 relative to part 102 in a reliable,predictable and simple way.

Insertion of the guide wire assembly 10 into a body lumen normally takesplace while gap ΔL between complementary surfaces 106 and 107 abut oneanother. As soon as the guide wire assembly 10 is in place, lock 103 isreleased and the tool of combined proximal and distal parts 101, 102 isremoved from the guide wire. At that moment the anchoring section 16will be active; moreover, a catheter or related medical device may beapplied over the guide wire assembly 10 and inserted into the patient.Catheters or related devices can be slid over the guide wire assembly 10until it reaches the expanded anchoring section 16; to advance itfarther, the guide wire assembly 10 will need to be connected back intoits insertion (i.e., unexpanded) state. This would also be the case oncethe guide wire assembly 10 has to be removed through the catheter.

Referring next to FIGS. 10A and 10B, alternative ways of locking theassembly 10 are shown. In these variants, a releasable proximal lock forthe control wire 14 replaces the permanent stop 92 used in FIG. 9, whichdue to its fixed attachment, can not be modified by the operator onceattached. Referring with particularity to FIG. 10A, a detail of theproximal end 91 of a guide wire assembly 10 shows how actuation can alsobe achieved by a long control element, such as a flexible wire 14 (made,for example, of a high strength polymer). If no pull force is appliedproximally, the assembly 10 will be in the insertion state. At theproximal end, the sheath 13 may have a short tapered slit 130 in itswall, in which the operator can lock the control element. This can bedone by first applying the necessary axial force for actuation of theguide wire assembly 10 and than bending the wire 14 sideward until itlocks itself in the slit 130. The friction will then hold the wire 14stationary locked in the tube wall.

Referring with particularity to FIG. 10B, yet another embodiment of theremovable lock is shown, where the wire 14 may include a tapered slidingstop 109 that fits tight inside the proximal end 91 of the sheath 13while deforming elastically. This elastic deformation will then increasethe friction between the sliding stop 109 and the wire 14, enough tolock the assembly 10 into its anchored or steered position. The frictioncan also be lowered again by pulling the tapered stop 109 a little bitout of the sheath 13, so that readjustment is possible. The sliding stop109 may also be provided with longitudinal slots to make it easier todeform elastically.

Referring next to FIG. 7, another embodiment of anchoring section 16 andsteerable section 17 of sheath 13 is shown. Close to distal end 12, ashort steerable section 17 is attached to helical anchoring section 16.Helical section 16 is shaped to have a smooth elastic contact with thesurrounding lumen or related tissue. In this instance, the pattern ofslots (not shown) will be configured to produce a differently bendingpattern from the one shown in FIGS. 2, 5 and 6. Techniques to producethe patterned slots, such as by laser cutting similar to those used formaking stents and related endoluminal prosthetic devices, may beemployed. Other methods, such as mechanical cutting with fine blades,may also be used. While the above-mentioned cutting techniques areespecially well known for metals, it will be appreciated by thoseskilled in the art that the guide wire assembly 10 of this invention maybe made of different materials, like polymers, or even combinations ofdifferent materials entailing known, concomitant production techniquesas needed.

Referring next to FIG. 11, an alternate embodiment anchoring section 110is disclosed. In the anchoring section 16 of the previous embodiments,blood or related body fluid can flow freely around, resulting in a verysmall resulting force caused by the pressure difference over theanchoring section 16. In some cases, especially in very thin arteries,it may be difficult to maneuver the guide wire assembly 10 to a remoteplace; in such cases, it can be advantageous to use the blood flow topull the guide wire assembly 10 into the target location. By placing athin cone-shaped polymer skin 113 onto the struts forming basket 112anchoring section 110, a parachute-like bag is formed. Through the useof a tool (such as tool 100 shown in FIG. 10), the basket 112 can bedeployed to a partially-deployed state in a manner similar to thatpreviously discussed. The forces associated with fluid flow (representedby the arrow in the figure) in the lumen (such as an artery) 111 can beused if the anchoring section 110 is brought into thispartially-deployed state where, although not touching the inner wall oflumen 111, has enough of an increased radial dimension perpendicular tothe major axis to take advantage of the force produced by the fluidflow.

The cone-shaped polymer skin 113 is attached distally to the struts atattachment sites 114 close or at the place where the diameter of thebasket 112 is greatest. The fluid that gets trapped in the bag formed bybasket 112 and polymer skin 113 will pull the guide wire assemblydownstream as it fills with blood or related fluid. The advantage isthat this reduces or eliminates the need for the operator to applyproximal pushing on the guide wire assembly. The other features,including the aforementioned steerability and anchoring, can still beused. Upon anchoring of guide wire assembly, the expanded polymer skin113 may completely occlude the target artery, while in an alternateembodiment of the invention, the geometry of the basket 112 and polymerskin 113 may be chosen so that perfusion always remains around thepolymer skin 113, even when the anchoring section 110 is deployed. Bothvariants are intended as embodiments of the invention, with theperfusion variant discussed in more detail next.

In FIG. 12, a variant on the design of FIG. 11 is given, where aparachute-like bag can still be used, but in which it is combined with afiltering function. Now the anchoring section 120 is provided with anexpandable basket 122, distally covered with a filter bag 123, which isattached to the basket near the attachment points 124. The differencewith the embodiment of FIG. 11 is that the filter bag 123 is nowprovided with a series of small patterned holes 125 to give the filterbag 123 its filtering functions. Such holes 125 have multiple functions.First, they prevent the full occlusion of fluid flow as mentioned above.Further, they can be used to filter emboli and related particulatematter with a predetermined minimum diameter. This is especiallyinteresting if the guide wire assembly is used in combination with acatheter for angioplasty, stenting or related procedures. The geometryand quantity of holes 125 depend on the size of the particles that haveto be caught, as well as on the desirable level of flow that needs tocontinue when the filter bag 123 is deployed. The available surface areain the filter bag 123 for making such holes further depends on thegeometry of the filter bag 123; for example, if bag 123 has a longconical shape as shown, it will allow the presence of a large number ofholes 125. In another embodiment, the filter may be made of a wire meshinstead of a perforated polymer layer. Such a wire mesh filter may beattached directly to the anchoring section struts in a manner similar tothe polymer layer. Alternatively, a wire mesh filter may be integratedwith the anchoring section, wherein the wire mesh structure becomesexpandable by the same relative axial displacement between the controlelement and the surrounding sheath.

The following drawings will eludicate the construction of the assembly10, clearly showing the corresponding points of attachment of thecontrol wire 14 and the surrounding sheath 13. Referring withparticularity to FIG. 9 a, the proximal end 11 of FIG. 9 and the distalend 12 of FIG. 8 are shown assembled together. For clarity, the longmid-section of control wire 14 and sheath 13 are left out of the drawingin order to enable visualization of the relevant parts at the opposingends. Referring with particularity to FIG. 9 a in conjunction with FIG.1, the distal end 12 of the device has a floppy tip 17 a, which extendsdistally beyond the connector 17 b of steerable section 17, where suchsteerability features are shown in FIGS. 2, 5 and 6. In the free statedepicted in FIG. 9 a, the assembly 10 is self-activated such that thelength of sheath 13, if measured between the corresponding points ofattachment, is equal to the length of the control wire 14, while thebias spring 15 has length L1, as shown in FIG. 9. In addition, thebasket 80 of anchoring section 16 is in the expanded state, such asshown in FIG. 8. Control wire 14 is connected to sheath 13 at theproximal end 91 of guide wire assembly 10 at the permanent stop 92 inFIG. 9, and at connector 32 that is situated in the crimped end 33 inFIG. 8.

Referring with particularity to FIGS. 9 b and 9 c, sheath 13 (FIG. 9 b)is shown detached from wire 14 (FIG. 9 c). In such detached state, thesheath 13 would become longer for two reasons. First is the unloading ofthe proximal bias spring 15, from length L1 into length L, both of whichare depicted in FIGS. 9 and 9 a, and both of which allow the overalllength from the proximal and distal ends 11, 12 to extend, as shown bythe increased length at the proximal side in FIG. 9 b relative to FIG. 9a. Second, there is the elongation of the basket section 80 at thedistal side as it stretches out axially from its radially expanded shapein FIG. 9 a to its radially contracted shape in FIG. 9 b. This latterfeature is due, as previously discussed, to guide wire assembly 10 beingpre-loaded to keep the wire 14 in a state of tension through attachmentto the corresponding end of sheath 13. After attachment, elastic biassection (presently shown in the form of a compressed spring) 15 attemptsto return to length L. In so doing, the bias force created by thecompressed spring 15 produces a tension load in wire 14 that exceeds theforce needed to expand the anchoring section 16 relative to the shapeshown in FIG. 9 b. Thus, but for the tendency of the wire 14 to pull theproximal and distal ends of sheath 13 toward one another, sheath 13assumes a longer length (as shown in FIG. 9 b relative to FIG. 9 a).

FIG. 9 c shows the control wire 14 removed from the guide wire assembly10 of FIGS. 1, 8 and 9. While the length of wire 14 may be subject tominor variations upon loading and unloading, such length change is verysmall relative to the length changes of sheath 13 that are produced bylength changes in spring 15 and basket 80. By preloading the bias spring15 and the expandable basket 80 to the state as shown in FIG. 9 a, itbecomes possible to line up the ends of the elongated element 13 of FIG.9 b with the corresponding ends of wire 14 of FIG. 9 c, whereafter thestep of attachment of sheath and wire 13 and 14 at the respective pointstakes place by one of the methods previously mentioned, such as gluing,welding, crimping or the like.

Referring next to FIG. 13 in conjunction with FIGS. 2 through 6,bendable region X of steerable section 17 is shown immediately distal ofbasket section 80. Such an embodiment gives a combination of ananchoring section and a steerable tip to the guide wire assembly 10, aspreviously discussed. FIGS. 13 a through 13 e show the severalintermediate stages of activation of such an assembly 10, with FIGS. 13b through 13 e showing with more particularity the tool 100 of FIG. 10attached over the proximal end 11 in order to partially or entirelysteer, collapse and deploy the assembly 10. Tension force changes in thecontrol wire 14 will bend the tip at relatively low force (as shown inFIGS. 13 c and 13 d), while increasing the force will finally also causeexpansion of the anchoring section 16 (as shown in FIGS. 13 b andfinally 13 a). Thus, the two extreme states of the device are theself-activated position of FIG. 13 a and the fully stretched tip andcollapsed basket section of FIG. 13 e, where the latter is the stateused for initial insertion of the assembly 10. Removal or otherdisconnection of the tool 100 from the assembly 10 will cause theassembly 10 to revert into the state depicted in FIG. 13 a, as spring 15will change from fully compressed length L2 of FIG. 13 e into length L1of FIG. 13 a, moving the tip and basket section accordingly such thatthe assembly 10 can act as a self-activating distal protection filterwith steerable tip for enhanced navigation, amongst others.

It will be appreciated by those skilled in the art having regard to thisdisclosure that other modifications of this invention beyond theseembodiments specifically described herein may be made without departingfrom the spirit of the invention. Accordingly, such modifications areconsidered within the scope of the invention as limited solely by theappended claims.

1. A medical device for use in a body lumen, said device comprising: atubular sheath comprising: a proximal end; a distal end opposite saidproximal end; at least one reconfigurable section disposed intermediatesaid proximal and distal ends; and an elastic bias section disposedproximal relative to said reconfigurable section, said elastic biassection configured to vary the axial length of said reconfigurablesection; and an elongate control element defining a proximal end and adistal end, said control element sized to allow longitudinal placementthereof within said sheath, said sheath and control element fixedlyattached to one another at substantially opposing ends thereof such thata tensile force is imposed by said sheath on said control elementthrough said fixed attachment, said tensile force sufficient to biassaid reconfigurable section in an expanded first shape that can beovercome by imparting an external force on said sheath through saidelastic bias section such that said medical device assumes a secondshape different from said first shape.
 2. The device of claim 1, whereinsaid control element comprises a wire.
 3. The device of claim 2, whereinthe distal end of said wire is fixedly attached to the correspondingdistal end of said sheath, and the proximal end of said wire is fixedlyattached to the corresponding proximal end of said sheath while saidelastic bias section is in an axially compressed state, therebyeffecting said tensile force upon said wire.
 4. The device of claim 3,further comprising a tool coupled to at least one of said wire or saidsheath, said tool configured to regulate relative axial positionsbetween said wire and said sheath and thereby effect transition betweensaid first shape and said second shape.
 5. The device of claim 4,wherein said tool comprises indicia configured to apprise a user of anamount of bias extant in said elastic bias section.
 6. The device ofclaim 4, wherein said tool comprises indicia configured to apprise auser of an amount of deformation extant in said second shape.
 7. Thedevice of claim 4, wherein said tool comprises a connector to facilitateremovable attachment of said tool to said at least one of said wire orsaid sheath.
 8. The device of claim 7, wherein said connector comprisesa lock.
 9. The device of claim 8, wherein said lock comprises a threadedconnection between said tool and said sheath.
 10. The device of claim 1,where said reconfigurable section comprises a steerable section disposedadjacent said distal end of said sheath.
 11. The device of claim 10,wherein said first shape comprises a bend in at least a portion of saidsteerable section.
 12. The device of claim 11, wherein said steerablesection comprises a plurality of steerable regions within saidreconfigurable section.
 13. The device of claim 12, wherein said bendsformed in each of said plurality of steerable regions are biased indirections independent of the remainder of said plurality of steerableregions.
 14. The device of claim 12, wherein said first shape comprisesa bend in a plurality of said plurality of steerable regions.
 15. Thedevice of claim 10, wherein said steerable section defines at least oneslot formed in said sheath.
 16. The device of claim 15, wherein said atleast one slot defines at least one of an axial, tangential orcircumferential slot.
 17. The device of claim 16, wherein anglesdefining said at least one slot comprise a plurality of differentangles, all oriented between 0 and 90 degrees with the longitudinal axisof said sheath.
 18. The device of claim 10, wherein said steerablesection comprises a coil spring disposed in said sheath.
 19. The deviceof claim 18, further comprising a rigidity element disposedasymmetrically in said coil spring to define a preferential direction ofsaid bend.
 20. The device of claim 10, wherein said steerable sectionfurther comprises a longitudinal reinforcement disposed asymmetricallyalong the outer surface of said sheath.
 21. The device of claim 1, wheresaid reconfigurable section of said sheath comprises an anchoringsection configured to assume an expanded state when said medical deviceis in said first shape and an unexpanded or less expanded state whensaid medical device is in said second shape.
 22. The device of claim 21,whereupon said expanded state comprises a substantially radiallyexpanded state.
 23. The device of claim 21, whereupon said expandedstate comprises a substantially helical shape.
 24. The device of claim21, wherein said anchoring section comprises a mesh layer configured asa collapsible basket.
 25. The device of claim 21, wherein said anchoringsection comprises a plurality of struts with slots defined therebetween.26. The device of claim 25, wherein said plurality of struts areoriented along a substantially axial dimension of said sheath.
 27. Thedevice of claim 25, wherein said anchoring section comprises a wire meshdisposed over said struts.
 28. The device of claim 25, wherein saidanchoring section further comprises a flexible layer disposed over saidstruts.
 29. The device of claim 28, wherein said flexible layercomprises a polymer material.
 30. The device of claim 29, wherein saidpolymer layer is configured as a filter, said filter defining aplurality of perforations within its surface.
 31. The device of claim29, wherein said flexible polymer layer is configured as a bag with anopen proximal entrance mouth and a closed distal end.
 32. The device ofclaim 31, wherein the proximal entrance mouth of said bag is coupled tosaid struts at a distal location relative to a largest diameter definedby said struts in said expanded state.
 33. The device of claim 1, wheresaid reconfigurable section of said sheath comprises a steerable sectionand an anchoring section, said steerable section distally disposedrelative to said anchoring section.
 34. The device of claim 33, whereinat least one of said steerable and anchoring sections is elasticallydeformable in response to said variation of said tensile force.
 35. Thedevice of claim 1, further comprising an endoluminal device configuredto slidably fit over said sheath.
 36. The device of claim 35, whereinsaid endoluminal device is selected from the group consisting of acatheter, steerable tip, stent, filter, angioplasty balloon, drain,dilator, filter, basket, anchor, floating anchor, occlusion device,guide wire, stylet, electrode, lead, drain, catheter sheath for use withcatheter introducers or a drug infusion catheter, and combinationsthereof.
 37. The device of claim 1, wherein said device is selected fromthe group consisting of a catheter, steerable tip, stent, filter,angioplasty balloon, drain, dilator, filter, basket, anchor, floatinganchor, occlusion device, guide wire, stylet, electrode, lead, drain,catheter sheath for use with catheter introducers or a drug infusioncatheter, and combinations thereof.
 38. The device of claim 1, whereinmaterials making up said control element are selected from the groupconsisting of polymers, metals and combinations thereof.
 39. The deviceof claim 38, wherein said metal is a shape-memory metal.
 40. The deviceof claim 1, wherein materials making up said sheath are selected fromthe group consisting of polymers, metals and combinations thereof. 41.The device of claim 40, wherein at least a portion of saidreconfigurable section comprises a shape-memory metal.
 42. The device ofclaim 1, wherein said imparted external force comprises a reduction insaid tensile force.
 43. The device of claim 1, wherein said second shapeis a substantially undeformed shape.
 44. The device of claim 1, whereinsaid second shape is a partially deformed shape.
 45. A guide wireassembly for use in a body lumen, said assembly comprising: a tubularsheath defining a proximal end, a distal end and at least onereconfigurable section disposed intermediate said proximal and distalends; a wire defining a proximal end and a distal end, said wire andsaid sheath fixedly attached to one another at substantially opposingends thereof such that a tensile force is imposed by said sheath on saidwire through said fixed attachment, said tensile force sufficient tobias said reconfigurable section in an expanded first shape; and anelastic bias section cooperative with said sheath and configured suchthat upon application of a variation in said tensile force throughmovement of said elastic bias section relative to said sheath, saidreconfigurable section assumes a second shape that is less expanded thansaid first shape.
 46. The assembly of claim 45, further comprising atool coupled to said elastic bias section to control said variation insaid force between said sheath and said wire.
 47. The assembly of claim45, wherein said at least one reconfigurable section comprises asteerable section disposed adjacent said distal end of said assembly,said steerable section bendably responsive to said variation in saidforce.
 48. The assembly of claim 47, wherein said at least onereconfigurable section further comprises an anchoring section expandablyresponsive to said variation in said force.
 49. The assembly of claim45, wherein said at least one reconfigurable section comprises ananchoring section expandably responsive to said variation in said force.50. The assembly of claim 49, wherein said anchoring section isconfigured to assume a substantially expanded state when said assemblyis in said first shape, and a reduction in said expanded state when saidassembly is in said second shape.
 51. The assembly of claim 50, whereinsaid reduction in said expanded state comprises an unexpanded state. 52.The assembly of claim 45, wherein said elastic bias section is formed insaid sheath.
 53. A medical device comprising: a hollow elongate memberdefining at least one reconfigurable section therein; an elongatecontrol element sized to fit longitudinally in said hollow elongatemember, wherein said hollow elongate member and said elongate controlelement are fixedly attached to each other at respective proximal endsand distal ends such that a state of tension exists between saidelongate control element and said hollow elongate member; and an elasticbias member coupled to said hollow elongate member between said proximalend and said at least one reconfigurable section such that absent anyexternal force being imparted to said device, said bias member causessaid state of tension to be overcome in said device to place said atleast one reconfigurable section into an expanded state that isdifferent from an insertion state.
 54. The device of claim 53, whereinsaid reconfigurable section is located intermediate said proximal anddistal ends of said elongate member and cooperative with said elasticbias section such that relative movements between said elongate controlelement and said elongate member produce a change in shape of saidreconfigurable section.
 55. The device of claim 54, further comprising aremovable tool for length control and consequent change in shape of saidreconfigurable section.
 56. The device of claim 55, wherein said changein shape of said reconfigurable section comprises a change into saidinsertion state that is suitable for inserting into and removable from abody lumen.
 57. The device of claim 55, wherein the tool cooperates withsaid elastic bias section to produce intermediate positions for saidreconfigurable section, said intermediate positions definingreconfigurable section configurations between said deformed expandedstate and said insertion state.
 58. The device of claim 55, whereuponremoval of said tool, said reconfigurable section is configured toremain in said body lumen.
 59. The device of claim 58, furthercomprising a treatment device configured to be deployed inside said bodylumen over said proximal end of said elongate member while saidreconfigurable section remains in said body lumen.
 60. The device ofclaim 59, wherein said treatment device is selected from the groupconsisting of a catheter, stent, filter, angioplasty balloon, drain,dilator, filter, basket, anchor, floating anchor, occlusion device,guide wire, stylet, electrode, lead, drain, catheter sheath for use withcatheter introducers or a drug infusion catheter, and combinationsthereof.
 61. The device of claim 60, wherein said tool is applied tocontrol the geometry of said reconfigurable section while either or bothof said device and said treatment device are moved through or positionedin said body lumen.
 62. The device of claim 60, wherein said toolcomprises a display configured to inform an operator about anoperational status of said reconfigurable section.
 63. The device ofclaim 54, wherein said reconfigurable section comprises: a plurality ofsteerable sections, each of said plurality of steerable sectionsresponsive to different levels in force between said elongate member andsaid control element; and an expandable anchoring section responsive tochanges in said state of tension between said elongate member and saidcontrol element.
 64. The device of claim 63, wherein at least one ofsaid plurality of steerable sections defines a pattern of slots formedin a wall of said elongate member.
 65. The device of claim 63, whereinat least one of said plurality of steerable sections comprises anadditional asymmetric reinforcing element.
 66. The device of claim 65,wherein said asymmetric reinforcing element is disposed on the outersurface of said elongate member.
 67. The device of claim 63, whereinsaid anchoring section comprises: a basket comprising a plurality ofstruts configured to facilitate changes of shape between a firstdeformed shape and a second shape; and a flexible polymer layer disposedover at least a portion of said basket, said layer defining an openproximal entrance mouth.
 68. The device of claim 67, wherein saidproximal entrance mouth is located distal of a radially widest portionof said basket.
 69. The device of claim 68, wherein said polymer layeris configured as a bag, said bag configured to form a pressuredifference between proximal and distal sides of said bag.
 70. The deviceof claim 69, wherein said bag is used to at least partly occlude a bodylumen.
 71. The device of claim 67, wherein said polymer layer definesapertures in a surface thereof.
 72. The device of claim 71, wherein saidpolymer layer is configured as a bag coupled to said anchoring section,said bag adapted for use as a filter for catching debris that passthrough said body lumen.
 73. The device of claim 53, wherein materialsmaking up said hollow elongate member and said elongate control elementare selected from the group consisting of polymers, metals, metals withenhanced radio-opacity features and combinations thereof.
 74. The deviceof claim 73, wherein said elongate control element may be made from adifferent material than said hollow elongate member.
 75. The medicaldevice of claim 53, wherein the length difference of said hollowelongate member and said elongate control element can be adjusted at ornear a proximal fixation end of said device by a releasable lockingmeans.